UK flight delay update: NATS confirms Prestwick connectivity issue now fixed but delays persist

Flights across the UK were disrupted on Monday, September 21, following a technical failure at the National Air Traffic Services (NATS) Prestwick centre in Scotland.

This marks the second significant incident in less than two weeks.

NATS confirmed a “connectivity issue with part of our systems network” caused the disruption, impacting airports across Scotland, Northern Ireland, and northern England.

The glitch was resolved by late morning; however, there were still delays and cancellations as some of the systems were rebooted. NATS stated that the problem had "nothing to do" with the software glitch at their Swanwick facility on 8 September, resulting in 2,000 cancelled flights and affecting hundreds of thousands of passengers.

The airlines responded angrily. Ryanair, which experienced over 140 delayed flights and affected 25,000 passengers, once again urged NATS chief executive Martin Rolfe to resign. "The incident once again raises questions about the resilience of NATS' systems," said EasyJet. "Urgent and accountable action is needed", said Steve Heapy of Jet2. "We will be sending another bill to NATS."

Airlines UK trade association said that the passengers and airlines "deserve better," while British Airways called the fault "disappointing." The Transport Secretary, Heidi Alexander, described the disruption as "deeply frustrating" but admitted that the problem had been solved.

Passengers at Glasgow, Edinburgh, Manchester, Belfast, and Bristol faced cancellations and delays of up to two hours. The incident intensifies pressure on NATS, which handles 2.5 million flights annually. With two major failures in a fortnight, questions over the resilience of UK air traffic control infrastructure are escalating.